August 19, 2001 11:00 pm

By Gary Fletcher

Observer Staff Writer

ENTERPRISE The Horse Creek Fire grew to 15,310 acres and came within a mile of the town of Imnaha over the weekend, but no structures were lost and there have been no injuries, said John See, U.S. Forest Service fire information officer.

The 380 people working on the fire were helped by some slight precipitation Saturday night. Therefore a backburn that was planned for Sunday was canceled.

There is a cold line around the town of Imnaha and the fire is 40 percent contained, See said. Six miles of fire line remain to be built from Cayuse Flat to Horse Creek.

The fire is expected to be contained by Friday.

The fire was started by lightning about 4 p.m. Aug. 14. It has been mostly a grass fire burning in some timbered draws. The fire has been kept between Horse Creek and the Imnaha River.

The one exception was Friday when the fire spotted across to the west side of the Imnaha River. The Union Hot Shots supported by two loads of retardant dropped from air tankers contained the spot fire at 100 acres. It is now being mopped up, See said.

The fire activity today is expected on the south and east ends where there is more timber, See said, adding that possible wind gusts today are a concern. If the fire gets into the timber, flame lengths and fire intensity will increase, particularly if the crowns of the trees should become involved, See said.

Three residences and eight other buildings are still listed as possibly threatened. However, fire officials plan to release by Tuesday the remainder of 80 people and the engines brought in for structure protection.

Two task forces were released Sunday night. Another is expected to be released today. One task force of five engines will remain today.

Overall it looks real good, See said.

The Oregon Conflagration Act was invoked Friday by Gov. John Kitzhaber, bringing fire departments from Idaho and across Oregon to protect structures.

An overhead team under the authority of the Oregon State Fire Marshals Office arrived at the fire Saturday as did four task forces totaling 20 engines from the rural fire districts of La Grande, Cove, Imbler, Joseph and Enterprise. Also responding were fire departments from Ontario, Tualatin, Cornelius, Washington County, Forest Grove, Gaston, Sheridan, Newberg, Willamina, Dundee, McMinnville and Dayton, Payette, Idaho, Fruitdale, Idaho, and Weiser, Idaho.

Before the reinforcements arrived, there were nine hand-crews, 13 engines and six dozers working the fire. The fire is well away from the Eagle Cap Wilderness Area, which is Oregons largest, but it is on the edge of the Hells Canyon National Recreation Area.

Wallowa County Sheriffs deputies have been manning roadblocks 24 hours a day at the town of Imnaha. The Hat Point Road Forest Service Road 4240 and the Lower Imnaha Road are closed because of heavy fire traffic.

Total cost of the fire as of 4:30 p.m. Sunday was $522,457, See said.